EDI Transmission

Once the EDI document has been translated into the agreed upon standards, you must then transmit this document to your trading partner. For many years, the most common means for doing this transmission was either a VAN (Value Added Network) or FTP (File Transfer Protocal). However you can use any means you and your trading partner agree upon. When working with the big box retailers, most will still accept VAN transmission, however many are moving to alternatives such as AS2.

VAN

A Value Added Network is essentially a post office. They receive a document from their customer usually via some sort of encrypted FTP or AS2, match up the Receiver ID to an ID they have setup within their master tables, and route the documents accordingly. This could mean simply placing into the mailbox of another one of their clients - if both of the trading partners happen to use the same VAN service - or routing to another VAN so they can deliver the document. For this service, you will probably be charged for a mailbox on your VAN, as well as pay for every K-Char (Kilo-character, or size of the file) that is sent and received. The major advantage of the VAN is the archiving capabilities they provide in case you find you have lost an interchange and need to reprocess. The obvious downside is the cost that is incurred for the services.

Encrypted FTP

Due to regulations set out in Sarbanes-Oxley, if you choose to use FTP to transmit your documents it should be encrypted. EDI documents often carry information that need to be protected, and therefor regular FTP should be avoided (although I see new FTP connections setup all the time). Although all different forms of encryption are used, most commonly I see FTP with SSL or FTP with PGP.

AS2

Quickly becoming a standard means of transmitting EDI documents, AS2 is much like encrypted FTP accept it uses an HTTP protocal instead of an FTP protocal. Because all forms of AS2 are encrypted, it requires the generation and exchange of public and private certificates. Instead of needing an FTP server for transmitting documents to, the AS2 software will run as a service on the machine listening to a designated port awaiting any communication from trading partners. Almost all big box retailers have AS2 capabilities but only a few, such as Wal-Mart, actually mandate it for their transmission. This can save a big company a lot of money in VAN fees since all communication is free over the internet, but the software is not cheap for the small suppliers to buy and implement. Because of this, some VANs have started offering AS2 services so suppliers can get around the initial cash outlay of purchasing the software.